Temporary tower at North Jetty holds radar

A tower with a marine radar on its top appeared at North Jetty at the end of September. Its purpose is to measure waves and to compare the data with corresponding movement of fiberoptic cables that rest all over the floor of Earth’s oceans. Photo by Zac Burtt/Siuslaw News

OSU team research conducted on behalf of U.S. Navy

Nov. 8, 2022 — Visitors to North Jetty Beach may have noticed a second tower in the parking lot, a few yards from the Coast Guard’s lookout tower.

According to Professor of Coastal Engineering Merrick Haller, from the Oregon State University (OSU) School of Civil & Construction Engineering, the tower holds a marine radar that is collecting wave data.

“On a ship you would use a radar to look for other ships, but we’re using it to look at the ocean and the waves in the ocean,” Haller said.

Haller is collaborating with a colleague, Dr. Meagan Wengrove, also of OSU’s Coastal Engineering program.

Wengrove, at the same time as Haller takes his measurements, is conducting distributed acoustic sensing on a fiberoptic cable that runs from the beach near Driftwood Shores to Alaska.

“They’re finding that you can actually use those cables to sense the ocean,” explained Haller. “As waves go across the cables, they change the strain on the cable. What my colleague Dr. Wengrove is doing is, she’s got a sampler that sends light pulses down to those cables and when they come back, they’re affected by the strain of the waves. Basically, in that data stream, you can see the waves as they affect the cable.”

The data Haller’s tower at North Jetty collects is then compared to the data that the slight movements of the underwater cables generate.

“We’re going to combine those two datasets and see what we can say about what’s going on in the interior of the ocean,” Haller said.

The research being conducted using the tower at North Jetty is being funded by the Office of Naval Research (ONR).

“They’re interested in using these cables to, for example, look for submarines,” said Haller. “There’s already so many of these cables down there and people are just starting to realize how much information can be gained from sampling them. The Navy is supporting us as we attempt to characterize those signals in the cables with what we see on the surface.”

The tower went up at the end of September and is expected to be removed this November.

Radars such as this can output imagery of something like a "birds-eye view" of the ocean surface. A team from OSU records this imagery to analyze changes in the ocean's surface over time. They operate a permanent station that monitors the Yaquina Inlet region in Newport, in cooperation with USCG Station Yaquina Bay, and funded by the Northwest Association of Ocean Observing Systems (NANOOS, see www.nanoos.org/). Near-real-time imagery and timelapse movies from that radar may be accessed at https://research.engr.oregonstate.edu/haller/Newport.

For more information on the Oregon State University Coastal Engineering program, go to cce.oregonstate.edu/coastal-and-ocean-research.